Then you may be using it wrong as it works fine for me; but how you're doing it wrong -- I've no idea without code. I suggest that you show your attempt with a Swing Timer in a small bit of compilable code that we can run unaltered on our own computers. Also, describe as best possible what effect you're trying to achieve here (sorry, but it's not clear to me), and why you're using a JEditorPane rather than the simpler JTextArea (you could have a very good reason, but again, it's not clear to me). Best of luck.